I have been running CCleaner since 2 years ago and it still doesn't clear out the Firefox cache. I am currently running Windows 7 Ultimate 64-bit and the version of CCleaner is 3.04.1389. I can always view the cache after a supposed "cleaning". My Firefox cache is located at "C:\Users\Account Name\Appdata\Local\Firefox". I am currently using a program called Eraser just for Firefox since CCleaner doesn't clean it. Firefox is not running in the background and have checked all the settings in CCleaner. I have CCleaner securely erase the files using the NSA 7-pass method. I would also like to know if there is a way that CCleaner could wipe out all the Windows Event View Log files. CCleaner does clear everything else in firefox though just not the cache.